Japanese Freshwater Triclads. 9 



of the frontal margin in the creeping state is less tlian half the 



greatest breadth of the trunk. Tlie trunk, which is dorsally 



convex and ventrally 



flat, very gradually z^^^TW?^ 



broadens posteriorly 



from the neck to aljout 



the region of the sexual 



organs. In the hind 



parts it tapers to a rather ^^^^^ ^g. ^ Ventral side of the anterior end of 



rounded eX^tremitV. Tlie Bddlocephalahrunneals.et K ab., showing adhesive 



folds and groove. 



body in the creepnig 



condition measured commonly 20-26 mm. long l-y 3-4 nun. 



broad at the broadest part. 



Colouration. — The dorsal surface of the body is of an olive- 

 like brown or sometimes velvety Idack colour, tlie parts containing 

 guts being usually darker than elsewhere. The ventral surface is 

 much paler than tJie dorsal. 



Eyes. — The two eyes, each lying in a white space, occupy a 

 position slightly in front of the neck-like constriction, the distance 

 between them being about twice as long as that between either of 

 the eyes and the nearest point in the frontal margin or that in the 

 lateral margin of the head. 



Body Wall. — The epidermis resting on a tine l)asement 

 membrane is somewhat thicker on the dorsal than on the ventral 

 side, and is, as usual, full of minute rhabdites. In the parenchyma 

 immediately beneath the dermal musculature there occur such 

 rhabdites as are still contained in their mother-cells, which exist in 

 wide distribution over various parts of the body. The dermal 

 musculatnre consists, as usual, of circular, transverse and longitudi- 

 nal layers. Situated in the parenchyma are eosinophil glandular 

 cells opening submarginally on the ventral surface, much as in the 

 preceding species. The anterior fold receiving the ducts of 

 numerous glands is not a true sucker, nor does the animal employ 

 its anterior end for the purposes of attachment to any greater degree 

 than the posterior or lateral margins of the body, along the ventral 

 surface of which numerous glands have their openings. In trutli, 



